Body mass index in relation to oesophageal and oesophagogastric junction adenocarcinomas: a pooled analysis from the International BEACON Consortium

BACKGROUND

Previous studies suggest an association between obesity and oesophageal (OA) and oesophagogastric junction adenocarcinomas (OGJA). However, these studies have been limited in their ability to assess whether the effects of obesity vary by gender or by the presence of gastro-oesophageal reflux (GERD) symptoms.

METHODS

Individual participant data from 12 epidemiological studies (8 North American, 3 European and 1 Australian) comprising 1997 OA cases, 1900 OGJA cases and 11 159 control subjects were pooled. Logistic regression was used to estimate study-specific odds ratios (ORs) and 95% confidence intervals (CIs) for the association between body mass index (BMI, kg/m(2)) and the risk of OA and OGJA. Random-effects meta-analysis was used to combine these ORs. We also investigated effect modification and synergistic interaction of BMI with GERD symptoms and gender.

RESULTS

The association of OA and OGJA increased directly with increasing BMI (P for trend <0.001). Compared with individuals with a BMI <25, BMI ≥40 was associated with both OA (OR 4.76, 95% CI 2.96-7.66) and OGJA (OR 3.07, 95% CI 1.89-4.99). These associations were similar when stratified by gender and GERD symptoms. There was evidence for synergistic interaction between BMI and GERD symptoms in relation to OA/OGJA risk.

CONCLUSIONS

These data indicate that BMI is directly associated with OA and OGJA risk in both men and women and in those with and without GERD symptoms. Disentangling the relationship between BMI and GERD will be important for understanding preventive efforts for OA and OGJA.

The importance of exposure rate on odds ratios by cigarette smoking and alcohol consumption for esophageal adenocarcinoma and squamous cell carcinoma in the Barrett's Esophagus and Esophageal Adenocarcinoma Consortium

BACKGROUND

Cigarette smoking is associated with esophageal adenocarcinoma (EAC), esophagogastric junctional adenocarcinoma (EGJA) and esophageal squamous cell carcinoma (ESCC), and alcohol consumption with ESCC. However, no analyses have examined how delivery rate modifies the strength of odds ratio (OR) trends with total exposure, i.e., the impact on the OR for a fixed total exposure of high exposure rate for short duration compared with low exposure rate for long duration.

METHODS

The authors pooled data from 12 case-control studies from the Barrett's Esophagus and Esophageal Adenocarcinoma Consortium (BEACON), including 1242 (EAC), 1263 (EGJA) and 954 (ESCC) cases and 7053 controls, modeled joint ORs for cumulative exposure and exposure rate for cigarette smoking and alcohol consumption, and evaluated effect modification by sex, body mass index (BMI), age and self-reported acid reflux.

RESULTS

For smoking, all sites exhibited inverse delivery rate effects, whereby ORs with pack-years increased, but trends weakened with increasing cigarettes/day. None of the examined factors modified associations, except for ESCC where younger ages at diagnosis enhanced smoking effects (P<0.01). For EAC and EGJA, ORs with drink-years exhibited inverse associations in <5 drinks/day consumers and no association in heavier consumers. For ESCC, ORs with drink-years increased, with trends strengthening with greater drinks/day. There was no significant effect modification, except for EAC and EGJA where acid reflux mitigated the inverse associations (P=0.02). For ESCC, younger ages at diagnosis enhanced drinking-related ORs (P<0.01).

CONCLUSIONS

Patterns of ORs by pack-years and drink-years, delivery rate effects and effect modifiers revealed common as well as distinct etiologic elements for these diseases.

Comparing different strategies for timing of dialysis initiation through inverse probability weighting

Dialysis has been used in the treatment of patients with end-stage renal disease since the 1960s. Recently, several large observational studies have been conducted to assess whether early initiation of dialysis prolongs survival, as compared with late initiation. However, these studies have used analytic approaches which are likely to suffer from either lead-time bias or immortal-time bias. In this paper, the authors demonstrate that recently developed methods in the causal inference literature can be used to avoid both types of bias and accurately estimate the ideal time for dialysis initiation from observational data. This is illustrated using data from a nationwide population-based cohort of patients with chronic kidney disease in Sweden (1996-2003).

A method for metagenomics of Helicobacter pylori from archived formalin-fixed gastric biopsies permitting longitudinal studies of carcinogenic risk

The human microbiota has come into focus in the search for component causes of chronic diseases, such as gastrointestinal cancers. Presumably long induction periods and altered local environments after disease onset call for the development of methods for characterization of microorganisms colonizing the host decades before disease onset. Sequencing of microbial genomes in old formalin-fixed and paraffin-embedded (FFPE) gastrointestinal biopsies provides a means for such studies but is still challenging. Here we report a method based on laser capture micro-dissection and modified Roche 454 high-throughput pyrosequencing to obtain metagenomic profiles of Helicobacter pylori. We applied this method to two 15 year old FFPE biopsies from two patients. Frozen homogenized biopsies from the same gastroscopy sessions were also available for comparison after re-culture of H. pylori. For both patients, H. pylori DNA dissected from FFPE sections had ∼96.4% identity with culture DNA from the same patients, while only ∼92.5% identity with GenBank reference genomes, and with culture DNA from the other patient. About 82% and 60% of the predicted genes in the two genomes were captured by at least a single sequencing read. Along with sequences displaying high similarity to known H. pylori genes, novel and highly variant H. pylori sequences were identified in the FFPE sections by our physical enrichment approach, which would likely not have been detected by a sequence capture approach. The study demonstrates the feasibility of longitudinal metagenomic studies of H. pylori using decade-preserved FFPE biopsies.

Smokeless tobacco (snus) and risk of heart failure: results from two Swedish cohorts

BACKGROUND

Oral moist snuff (snus) is discussed as a safer alternative to smoking, and its use is increasing. Based on its documented effect on blood pressure, we hypothesized that use of snus increases the risk of heart failure.

DESIGN

Two independent Swedish prospective cohorts; the Uppsala Longitudinal Study of Adult Men (ULSAM), a community-based sample of 1076 elderly men, and the Construction Workers Cohort (CWC), a sample of 118,425 never-smoking male construction workers.

METHODS

Cox proportional hazards models were used to investigate possible associations of snus use with risk of a first hospitalization for heart failure.

RESULTS

In ULSAM, 95 men were hospitalized for heart failure, during a median follow up of 8.9 years. In a model adjusted for established risk factors including past and present smoking exposure, current snus use was associated with a higher risk of heart failure [hazard ratio (HR) 2.08, 95% confidence interval (CI) 1.03-4.22] relative to non-use. Snus use was particularly associated with risk of non-ischaemic heart failure (HR 2.55, 95% CI 1.12-5.82). In CWC, 545 men were hospitalized for heart failure, during a median follow up of 18 years. In multivariable-adjusted models, current snus use was moderately associated with a higher risk of heart failure (HR 1.28, 95% CI 1.00-1.64) and non-ischaemic heart failure (HR 1.28, 95% CI 0.97-1.68) relative to never tobacco use.

CONCLUSION

Data from two independent cohorts suggest that use of snus may be associated with a higher risk of heart failure.

Alcohol intake and risk of oesophageal adenocarcinoma: a pooled analysis from the BEACON Consortium

BACKGROUND AND AIMS

Alcohol intake is a strong and well established risk factor for oesophageal squamous cell carcinoma (OSCC), but the association with oesophageal adenocarcinoma (OA) or adjacent tumours of the oesophagogastric junction (OGJA), remains unclear. Therefore, the association of alcohol intake with OSCC, OA, and OGJA was determined in nine case-control studies and two cohort studies of the Barrett's Esophagus and Esophageal Adenocarcinoma Consortium (BEACON).

MATERIALS AND METHODS

Information was collected on alcohol intake, age, sex, education, body mass index, gastro-oesophageal reflux, and tobacco smoking from each study. Along with 10,854 controls, 1821 OA, and 1837 OGJA, seven studies also collected OSCC cases (n=1016). Study specific ORs and 95% CIs were calculated from multivariate adjusted logistic regression models for alcohol intake in categories compared to non-drinkers. Summary risk estimates were obtained by random effects models. Results No increase was observed in the risk of OA or OGJA for increasing levels of any of the alcohol intake measures examined. ORs for the highest frequency category (≥ 7 drinks per day) were 0.97 (95% CI 0.68 to 1.36) for OA and 0.77 (95% CI = 0.54 to 1.10) for OGJA. Suggestive findings linked moderate intake (eg, 0.5 to <1 drink per day) to decreased risk of OA (OR 0.63, 95% CI 0.41 to 0.99) and OGJA (OR 0.78, 95% CI 0.62 to 0.99). In contrast, alcohol intake was strongly associated with increased risk of OSCC (OR for ≥ 7 drinks per day 9.62, 95% CI 4.26 to 21.71).

CONCLUSIONS

In contrast to OSCC, higher alcohol consumption was not associated with increased risk of either OA or OGJA. The apparent inverse association observed with moderate alcohol intake should be evaluated in future prospective studies.

H. pylori seropositivity before age 40 and subsequent risk of stomach cancer: a glimpse of the true relationship?

Stomach carcinogenesis involves mucosal and luminal changes that favor spontaneous disappearance of Helicobacter pylori. Therefore, the association between the infection and cancer risk might typically be underestimated. As acquisition of the infection almost invariably occurs before adulthood, the serostatus at age 16–40 should best reflect the lifetime occurrence of the infection. We therefore conducted a case-control study nested within a historic cohort of about 400,000 individuals who donated sera before age 40 to either of two large Swedish Biobanks between 1968 and 2006, and whose records were linked to complete nationwide registers. For each stomach adenocarcinoma case occurring at least 5 years after serum donation 2 controls were selected matched on age, sex and year of donation and biobank. Serum immunoglobulin G antibodies against H. pylori cell-surface antigens (Hp-CSAs) were measured with an enzyme–linked immunosorbent assay and antibodies against CagA with an immunoblot assay. Conditional logistic regression models were used to estimate odds ratios (ORs) for stomach adenocarcinoma among H. pylori infected relative to uninfected. We confirmed 59 incident cases of stomach adenocarcinoma (41 non-cardia tumors) during follow-up. ORs for non-cardia stomach adenocarcinoma among subjects with Hp-CSA antibodies (regardless of CagA serostatus), antibodies against CagA (regardless of Hp-CSA serostatus), and antibodies to both, relative to those who were seronegative to both, were 17.1 (95% confidence interval [CI] 4.0–72.9), 10.9 (95% CI 3.2–36.9), and 48.5 (95% CI 5.8–407.4), respectively. H. pylori infection is a much stronger risk factor for non-cardia stomach adenocarcinoma than initially realized. However, further studies are needed to answer whether it is a necessary cause, as the possibility of misclassification of H. pylori status could not be ruled out in our study.

No survival benefit from early-start dialysis in a population-based, inception cohort study of Swedish patients with chronic kidney disease

OBJECTIVE

To investigate how the timing of dialysis initiation is associated with mortality.

DESIGN

Population-based, prospective, observational cohort study.

SETTING

Clinical laboratories (n = 69) provided information on all patients in Sweden whose serum creatinine level for the first time and exceeded 3.4 mg dL(-1) (men) or 2.8 mg dL(-1) (women) between 20 May 1996 and 31 May 1998.

SUBJECTS

All patients (n = 901), aged 18-74 years, in whom the cause of serum creatinine elevation was chronic kidney disease, were included in the study; participants were interviewed and followed for 5-7 years.

MAIN OUTCOME MEASURES

Information on date of death was obtained from a national Swedish population register. Early-start dialysis [estimated glomerular filtration rate from serum creatinine (eGFR) ≥7.5 mL min(-1) per 1.73 m(2)] was compared to late start of dialysis (eGFR <7.5 mL min(-1) per 1.73 m(2)), and no dialysis. Relative risk [hazard ratio (HR)] of death was modelled with time-dependent multivariate Cox proportional hazards regression.

RESULTS

Mean eGFR was 16.1 mL min(-1) per 1.73 m(2) at inclusion and 7.6 mL min(-1) per 1.73 m(2) at the start of dialysis. Among the 385 patients who started dialysis late, 36% died during follow-up compared to 52% of 323 who started early. The adjusted HR for death was 0.84 [95% confidence interval (CI) 0.64, 1.10] among late versus early starters. The mortality among nondialysed patients increased significantly at eGFR below 7.5 mL min(-1) per 1.73 m(2) (HR 4.65; 95% CI 2.28, 9.49; compared to eGFR 7.5-10 mL min(-1) per 1.73 m(2)). After the start of dialysis, the mortality rate further increased. Compared to nondialysed patients with eGFR ≤15 mL min(-1) per 1.73 m(2), adjusted HR was 2.65 (95% CI 1.80, 3.89) for patients receiving dialysis.

CONCLUSION

We found no survival benefit from early initiation of dialysis.

Smoking, snus use and risk of right- and left-sided colon, rectal and anal cancer: a 37-year follow-up study

Although some authorities consider smoking to be an established risk factor for colorectal cancer, the international literature is not entirely consistent. Further, only 1 study has addressed the association with smokeless tobacco and none with Scandinavian moist snuff (snus). This retrospective cohort study included 336,381 male Swedish construction workers with detailed information on tobacco use at cohort entry in 1971-1992. Complete follow-up through 2007 was accomplished by means of linkage to population and health registers. Hazard ratios (HRs) and 95% confidence intervals (CIs) derived from Cox proportional hazards regression models estimated relative risks, adjusted for age and body mass index. Subjects who were never-users of any tobacco served as reference. After up to 37 years of follow-up, pure smoking was associated with a marginally increased risk of colon cancer (HR 1.08, 95% CI 0.99-1.19), a modestly elevated risk of rectal cancer (HR 1.16, 95% CI 1.04-1.30) and a substantial excess risk of anal cancer (HR 2.41, 95% CI 1.06-5.48). Snus use was not significantly associated with an increased risk of colorectal or anal cancer, although the point estimate for colon cancer was similar to that observed among smokers. Swedish data provide meager support for the association between tobacco use and colorectal cancer. A general tendency among Swedish men to quit smoking in recent decades might have attenuated true associations. A link between smoking and anal cancer was confirmed.

Risk of gastric cancer and peptic ulcers in relation to ABO blood type: a cohort study

Blood group A was found to be associated with gastric cancer in the 1950s. Strikingly, for peptic ulcers an increased risk has been shown for blood group O. However, previous investigations have generally been poorly conducted and have failed to take a unifying approach to these observations. Using the Scandinavian Donations and Transfusions (referred to as "SCANDAT") database, the authors established a cohort of Swedish and Danish blood donors with known blood type and followed these for the occurrence of gastric cancer and peptic ulcers through December 31, 2002. Cases were ascertained by using nationwide cancer and hospital registers. Altogether, 1,089,022 donors were followed for up to 35 years, during which 688 gastric cancer cases and 5,667 peptic ulcer cases accrued. Poisson regression analyses confirmed an increased risk of gastric cancer among individuals with blood group A (incidence rate ratio = 1.20, 95% confidence interval: 1.02, 1.42) and conversely that peptic ulcer risk was instead highest among those with blood group O. In this large, population-based cohort study, the authors have confirmed the association between blood group A and gastric cancer. In addition, they give further support to the notion that individuals with blood group O have a higher risk of peptic ulcers than those with other blood groups.

National surveillance of surgical-site infection through register-based analysis of antibiotic use after inguinal hernia repair

BACKGROUND

Systematic surveillance of surgical-site infections is not standard. The aim of this retrospective cohort study was to evaluate the feasibility of using existing national health registers for surveillance of postoperative antibiotic treatment suggestive of surgical-site infection.

METHODS

Data from national registers on hospital admissions and drug use were combined. Antibiotic purchases by 8856 patients subject to ambulatory care for inguinal hernia repair in Sweden during 2006 were ascertained during a 30-day interval immediately after surgery (postsurgical period) and in an 11-month control period (6 months before and 5 months after the postsurgical period).

RESULTS

The incidence of first purchases of skin and soft tissue antibiotics was 245 per 8697 person-months in the first postoperative month and 180 per 52 612 person-months in the preoperative control period, representing a 1-month risk difference of 2.4 (95 per cent confidence interval (c.i.) 2.0 to 2.7) per cent. Hence, a 1-month risk of 2.4 per cent could be attributed tentatively to the surgery. The rate of episodes with antibiotics used mainly for skin and soft tissue infection was sevenfold higher in the first postoperative month than in the control period (rate ratio 7.01, 95 per cent c.i. 5.94 to 8.27).

CONCLUSION

The risk of antibiotic treatment during the postsurgical period was of the same order of magnitude as infection rates reported in the Swedish Hernia Register and review studies. Surveillance of postoperative antibiotic use may be considered as a resource-saving surrogate marker for surgical-site infections or an indicator of inappropriate use.

Short-term natural history in women with symptoms indicative of pelvic organ prolapse

INTRODUCTION AND HYPOTHESIS

Information about the natural history of pelvic organ prolapse (POP) is scarce.

METHODS

This was a prospective cohort study of 160 women (mean age 56 years), whose answers in a population-based survey investigation indicated presence of symptomatic prolapse (siPOP), and 120 women without siPOP (mean age 51 years).

RESULTS

Follow-up questionnaire was completed by 87%, and 67% underwent re-examination according to pelvic organ prolapse quantification (POP-Q) system after 5 years. Among re-examining siPOP women, 47% had an unchanged POP-Q stage, 40% showed regression, and 13% showed progression. The key symptom "feeling of a vaginal bulge" remained unchanged in 30% of women with siPOP, 64% improved by at least one step on our four-step rating scale, and 6% deteriorated. Among control women, siPOP developed in 2%. No statistically significant relationship emerged between changes in anatomic status and changes in investigated symptoms.

CONCLUSION

Only a small proportion of women with symptomatic POP get worse within 5 years.

Cigarette smoking and adenocarcinomas of the esophagus and esophagogastric junction: a pooled analysis from the international BEACON consortium

BACKGROUND

Previous studies that showed an association between smoking and adenocarcinomas of the esophagus and esophagogastric junction were limited in their ability to assess differences by tumor site, sex, dose-response, and duration of cigarette smoking cessation.

METHODS

We used primary data from 10 population-based case-control studies and two cohort studies from the Barrett's Esophagus and Esophageal Adenocarcinoma Consortium. Analyses were restricted to white non-Hispanic men and women. Patients were classified as having esophageal adenocarcinoma (n = 1540), esophagogastric junctional adenocarcinoma (n = 1450), or a combination of both (all adenocarcinoma; n = 2990). Control subjects (n = 9453) were population based. Associations between pack-years of cigarette smoking and risks of adenocarcinomas were assessed, as well as their potential modification by sex and duration of smoking cessation. Study-specific odds ratios (ORs) estimated using multivariable logistic regression models, adjusted for age, sex, body mass index, education, and gastroesophageal reflux, were pooled using a meta-analytic methodology to generate summary odds ratios. All statistical tests were two-sided.

RESULTS

The summary odds ratios demonstrated strong associations between cigarette smoking and esophageal adenocarcinoma (OR = 1.96, 95% confidence interval [CI] = 1.64 to 2.34), esophagogastric junctional adenocarcinoma (OR = 2.18, 95% CI = 1.84 to 2.58), and all adenocarcinoma (OR = 2.08, 95% CI = 1.83 to 2.37). In addition, there was a strong dose-response association between pack-years of cigarette smoking and each outcome (P < .001). Compared with current smokers, longer smoking cessation was associated with a decreased risk of all adenocarcinoma after adjusting for pack-years (<10 years of smoking cessation: OR = 0.82, 95% CI = 0.60 to 1.13; and > or =10 years of smoking cessation: OR = 0.71, 95% CI = 0.56 to 0.89). Sex-specific summary odds ratios were similar.

CONCLUSIONS

Cigarette smoking is associated with increased risks of adenocarcinomas of the esophagus and esophagogastric junction in white men and women; compared with current smoking, smoking cessation was associated with reduced risks.

Dietary quercetin intake and risk of gastric cancer: results from a population-based study in Sweden

BACKGROUND

To study the impact of the dietary antioxidant quercetin on risk of gastric adenocarcinoma.

PATIENTS AND METHODS

Using data from a large Swedish population-based case-control study of gastric cancer (505 cases and 1116 controls), we studied the association between quercetin and risk of anatomic (cardia/noncardia) and histological (intestinal and diffuse) subtypes of gastric cancer.

RESULTS

We found strong inverse associations between quercetin and the risk of noncardia gastric adenocarcinoma, with an adjusted odds ratio (OR) of 0.57 (95% confidence interval 0.40-0.83) for the highest quintile (≥11.9 mg) of daily quercetin intake relative to the lowest quintile of intake (<4 mg quercetin/day), supported by a significant decreasing linear trend (P value < 0.001). Similar findings were observed for the intestinal and diffuse subtype. For cardia cancer, we found a less evident and nonsignificant inverse relationship. The protection of quercetin appeared to be stronger among female smokers, with the OR leveled of at values <0.2 in quintiles 3-5 (>6 mg quercetin/day).

CONCLUSIONS

High dietary quercetin intake is inversely related to the risk of noncardia gastric adenocarcinoma, and the protection appears to be particularly strong for women exposed to oxidative stress, such as tobacco smoking.

Interactive voice response and web-based questionnaires for population-based infectious disease reporting

The authors aimed to evaluate the web and an Interactive Voice Response (IVR) phone service as vehicles in population-based infectious disease surveillance. Fourteen thousand subjects were randomly selected from the Swedish population register and asked to prospectively report all respiratory tract infections, including Influenza-like Illness (ILI-clinical symptoms indicative of influenza but no laboratory confirmation), immediately as they occurred during a 36-week period starting October 2007. Participants were classified as belonging to the web or IVR group based on their choice of technology for initial registration. In all, 1,297 individuals registered via IVR while 2,044 chose the web. The latter were more often young and well-educated than those registered via IVR. Overall, 52% of the participants reported at least one infection episode. The risk of an infectious disease report was 14% (95% CI: 6, 22%) higher in the web group than in the IVR group. For ILI the excess was 27% (95% CI: 11, 47%). After adjustments for socio-demographic factors, statistically non-significant excesses of 1 and 8% remained, indicating trivial differences potentially attributable to the two reporting techniques. With attention to confounding, it should be possible to combine the web and IVR for simple reporting of infectious disease symptoms.

Duration of red blood cell storage and survival of transfused patients (CME)

BACKGROUND

Disquieting reports of increased complication and death rates after transfusions of red blood cells (RBCs) stored for more than 14 days prompted us to perform an observational retrospective cohort study of mortality in relation to storage time.

STUDY DESIGN AND METHODS

We conducted a cohort study utilizing data on all recipients of at least one RBC transfusion in Sweden and Denmark between 1995 and 2002, as recorded in the Scandinavian Donations and Transfusions (SCANDAT) database. Relative risks of death in relation to storage time were estimated using Cox regression, adjusted for several possible confounding factors.

RESULTS

After various exclusions, 404,959 transfusion episodes remained for analysis. The 7-day risk of death was similar in all exposure groups, but a tendency for a higher risk emerged among recipients of blood stored for 30 to 42 days (hazard ratio, 1.05; 95% confidence interval [CI], 0.97-1.12), compared to recipients of blood stored for 10 to 19 days. With 2-year follow-up, this excess remained at the same level (hazard ratio, 1.05; 95% CI, 1.02-1.08). No dose-response pattern was revealed and no differential effect was seen when the analyses were restricted to recipients of leukoreduced units only.

CONCLUSION

Although a small excess mortality was noted in recipients of the oldest RBCs, the risk pattern was more consistent with weak confounding than with an effect of the momentary exposure to stored RBCs. It seems, thus, that any excess mortality conferred by older RBCs in the combined Swedish and Danish transfusion recipient population is likely less than 5%, which is considerably smaller than in the hitherto largest investigation.

Nonobstetric risk factors for symptomatic pelvic organ prolapse

OBJECTIVE

To identify possible nonobstetric risk factors for symptomatic pelvic organ prolapse in the general female population.

METHODS

This was a population-based, cross-sectional study derived from a sample of 5,489 Stockholm women, 30 to 79 years old, who answered a validated questionnaire for the identification of symptomatic prolapse. The 454 women whose answers indicated the presence of such prolapse and the 405 randomly selected control participants with answers that gave no indication of prolapse received a 72-item questionnaire, which probed into a priori suspected risk factors. Only those women with intact uteri and no prior surgery for incontinence or prolapse were included. Multivariable logistic regression models estimated prevalence odds ratios (ORs) with 95% confidence intervals (CIs).

RESULTS

In addition to age and parity, overweight (prevalence OR for body mass index [kg/m] 26-30 compared with 19-25 was 1.9, 95% CI 1.2-3.1), history of conditions suggestive of deficient connective tissue (varicose veins/hernia/hemorrhoids, prevalence OR for positive history compared with no history 1.8, 95% CI 1.2-2.8), family history of prolapse (prevalence OR for positive history compared with no history 3.3, 95% CI 1.7-6.4), heavy lifting at work (prevalence OR for 10 kg or more compared with no heavy lifting 2.0, 95% CI 1.1-3.6), and presence of constipation, hard stools, or difficult evacuation (prevalence OR relative to normal bowel habits 2.1, 95% CI 1.4-3.3) all were linked independently, significantly, and positively to the presence of symptomatic prolapse.

CONCLUSION

In this nonconsulting population, age and parity were the dominating risk factors, but significant independent associations with markers suggestive of congenital susceptibility (family history and conditions signaling weak connective tissue) and nonobstetric strain on the pelvic floor (overweight/obesity, heavy lifting, and constipation) imply that individual predisposition and lifestyle/environment also may play an important role. The causal direction of the association with bowel habits remains uncertain, and the link to family history could be partly because of information bias.

Interleukin 1-beta gene polymorphisms and risk of gastric cancer in Sweden

OBJECTIVE

Helicobacter pylori (H. pylori) infection stimulates the production of interleukin (IL)-1 beta, a pro-inflammatory cytokine and suppressor of gastric acid secretion. As both inflammation and hypochlorhydria, which might facilitate proximal colonization of H. pylori and other bacterial species alike, have been implicated in gastric carcinogenesis, much attention has been directed to functional genetic polymorphisms that affect the production of IL-1 beta. The purpose of this study was to clarify the role of these polymorphisms.

MATERIAL AND METHODS

We analysed a population-based, case-control study in 5 Swedish counties and a hospital-based, case-control study conducted in 8 Swedish hospitals, with a total of 351 gastric cancer cases and 539 controls. The IL1B-31, IL1B-511 and IL1B+3954 biallelic polymorphisms were genotyped using pyrosequencing. The variable number of tandem repeats (VNTR) polymorphism of IL1-RN was analysed using polymerase chain reaction (PCR) followed by gel electrophoresis. Relative risks were estimated by odds ratios with 95% confidence intervals, derived from unconditional logistic regression.

RESULTS

The risk of gastric cancer was unrelated to genotype in all of the studied polymorphic loci, and the absence of any association was confirmed in both the population-based and hospital-based case-control studies. Analyses confined to histological subtypes (intestinal or diffuse) and site-specific tumours (cardia or distal stomach), as well as analyses stratified by H. pylori infection status and family history of gastric cancer, did not reveal any significant increases or decreases in risk.

CONCLUSION

Our results do not lend support to the hypothesis that human genetic polymorphisms related to the production of IL-1 beta are associated with the risk of gastric cancer.

Measures of physical activity and their correlates: the Swedish National March Cohort

We compared the results of self-estimates of physical activity obtained with a novel instrument (the Energy Expenditure Questionnaire, EEQ) to those obtained from questions typically asked in epidemiological investigations (reference method) in a cohort of 42,150 Swedish men and women, aged 18-94. In the EEQ, participants were asked to report total physical activity by estimating the total time during a typical day and night spent on different physical activity intensity levels from the lowest (corresponding to lying in bed, 0.9 Metabolic Energy Turnover; MET) to the highest, (exceeding the intensity of to shovelling snow by hand, i.e., >6 MET). As a comparison, they also estimated hours per week devoted to household chores, commuting and leisure time physical activities classified as; light, moderate and heavy. The average physical activity estimated with the EEQ was 1.36 MET or 32.6 METh/day or 2,341 kcal/day. In comparison, physical activity estimated with the reference method represented no more than 17% of this amount. The Spearman's correlation coefficient between the two measures was 0.26. Using EEQ, men reported significantly more physical activity than women (mean = 36.3 vs. 30.6 METh/day). Body mass index (BMI) > or = 25, education > or = 12 years, and age > or = 60 years were significantly associated with lower physical activity. Questions focusing on leisure time exercise and a few other selected activities provide estimates of activity that correlate poorly with self-reported total energy output from all physical activity and inactivity. Investigators need to be more explicit about which component of activity they investigate.